Text A. The cardiovascular system

The cardiovascular system is the system of blood circulation. By the cardiovascular system is meant the heart and the vessels – the arteries, the veins and the capillaries of the human body. The centre of the circulatory system is the heart. It is the most important muscle in the body. Without the heart and its circulatory system human life would not be possible.

The human heart is an inner hollow cone-shaped muscular organ placed within the chest just behind the breastbone and between the lungs and included in the pericardium. The base of the heart is against the third rib. Its apex is against the interspace between the fifth and the sixth costal cartilages. The weight of the heart is about 300 grams in the male and about 220 gr in the female.

The heart consists of two separate chambers divided by the septum. Each of the chambers has two connected parts; an upper chamber called the atrium or the auricle and a lower chamber called the ventricle. Each is made up of several layers of cardiac muscle arranged in circles and spirals. The atrioventricular valves separate the atria from the ventricles.

The right atrium is larger than the left one, but the walls of the left atrium are thicker than those of the right one. The right ventricle is triangular in form and has thick walls. The right ventricle is in the anterior part of the heart. The left ventricle is longer and more conical than the right one. The walls of the left ventricle are three times as thick as those of the right one.

Blood vessels receiving blood from the ventricle and leading it away from the heart towards other organs are arteries. They continue dividing and subdividing forming smaller and smaller vessels with thinner and thinner walls. The smallest arteries are the arterioles and these finally divide into capillaries. (“hairlike” – Latin) though actually they are much thinner than hair. Gradually the capillaries begin to join into larger vessels carrying blood to the heart from the organs. Such vessels are the veins. The smallest of these are the venules.

The vessels carrying blood to and from the tissues of the body compose the general system. They are called the vessels of the systemic circulation. The pulmonary circulation is formed by the vessels carrying blood to and from the lungs. The portal circulation is formed by the veins passing to the liver.

TASKS

I. Translate the following words and word combinations:

система кровообращения; самая важная мышца; жизнь была бы невозможна; внутренний полый конусообразный орган; верхушка и основание сердца; вес сердца; две отдельные камеры; разделенный перегородкой; стенки левого предсердия; передняя часть; сосуды, несущие кровь к сердцу; вены, идущие к печени; сосуды, принимающие кровь из желудочков; в три раза толще

II. Complete the sentences:

1. The … is the system of blood circulation.

2. The … is the most important muscle of the body.

3. The cardiovascular system consists of the heart and the ….

4. Without the heart the … would not be possible.

5. The heart is placed within the ….

6. The heart is included in the ….

7. The … of the heart is against the third rib.

8. The … of the heart is about 220-300 gr.

9. The heart consists of two ….

10. They are divided by the ….

11. The upper chamber is called the ….

12. The lower chamber is called the ….

13. The atrioventricular … separate the atria from the ventricles.

III. Match the line in A with that in B:

A B

1. Blood vessels carrying blood from 1. the portal circulation

the heart are …

2. Vessels carrying blood to the heart 2. the systemic circulation

are …

3. The veins passing to the liver form … 3. the veins

4. The vessels carrying blood to and 4. the arteries

from the lungs form …

5. The smallest and the thinnest vessels 5. the capillaries

are …

6. The vessels carrying blood to and from 6. the pulmonary circulation

the tissues of the body form …

IV. Express your agreement or disagreement:

1. The heart is not a muscle.

2. The heart is symmetrical.

3. The vessels include the veins, the arteries and the capillaries.

4. The human heart is an inner hollow organ placed within the abdomen.

5. The weight of the heart is less in the male than in the female.

6. The upper chamber of the heart is called the ventricle and the lower one is called

the atrium.

7. The right atrium is larger than the left one.

8. The right ventricle is in the posterior part of the heart.

9. The walls of the left ventricle are thicker than those of the right one.

10. Blood vessels carrying blood from the heart are veins.

11. The smallest vessels are called arteries.

12. The vessels carrying blood to and from the lungs are called the general

circulation.

V. Answer the questions:

1. What does the cardiovascular system consist of?

2. What vessels do you know?

3. What is the heart?

4. Where is the heart located?

5. What does the heart consist of?

6. What is the septum?

7. Where are the atria and the ventricles located?

8. What are atria?

9. What are ventricles?

10. What are capillaries?

11. What vessels compose the general system?

12. What vessels compose the pulmonary system?

13. What vessels compose the portal system?